The present invention relates to a check valve for an engine cooling system and more particularly to a check valve which is inserted in the cooling system to ensure positive venting of air out of the system.
Check valves are known which are secured in an opening in a high point of a cooling system for an engine, such as near the top of a radiator, in an auxiliary tank, or in some other point. The check valve typically includes a body, a reduced internal diameter portion in the body to prevent the ball element from dropping out of the body and into the cooling system, a retaining element for capturing the ball element in the valve body between the retaining element and the portion of reduced internal diameter and a ball element in the body, and some structure, such as screw threads, for securing the check valve in the opening. The retaining element includes an opening and a seat for the ball element defined around the opening, so that, when the system is under pressure, fluid pressure forces the ball element against its seat to prevent the loss of fluid from the system and/or the bypass of fluid around the radiator.
The check valve has the drawback that special provision must be made in the valve body for a reduced diameter portion which is small enough to prevent the ball element from leaving the chamber defined by the reduced internal diameter portion and the retaining member. In addition, there is often air in the cooling system which does not move to the top when the system is idle or being filled, but only when the engine is in operation and the cooling system is under pressure. Where the system employs the known check valves, the air is prevented from escaping the system when the engine is running since the ball element is seated, preventing the passage of all gases and liquids. Furthermore, the ball elements in some valves become stuck in their seated position, thereby preventing venting of the cooling system at all times, even when the system is not under pressure, such as during filling of the system.
In some applications, it is desirable for the check valve to control flow in the opposite direction or to be installed in a cooling system opening having a different diameter. Conventional cooling system check valves have no flexibility for such purposes. Moreover, these known check valves must be in a substantially vertical orientation in order to operate properly.